Heat treatment apparatus

Abstract

Disclosed is a heat treatment apparatus which includes a processing vessel having a furnace throat at its bottom and adapted to accommodate process objects therein to perform a heat treatment to the process objects under reduced pressure, the processing vessel having a vessel main body made of quartz, a metallic lid adapted to support thereon a holder for holding a plurality of process objects so as to load and unload the holder into and from the processing vessel and to close and open the furnace throat, and an annular sealing member disposed on the lid to seal a gap between the lid and the furnace throat. A contact-preventing member is disposed between the lid and the furnace throat to prevent contact of the lid with the furnace throat due to squashing of the sealing member that would otherwise occur when an internal pressure of the processing vessel is reduced.

Description

TECHNICAL FIELD[0001]The present invention relates to a heat treatment apparatus.BACKGROUND ART[0002]In manufacturing of semiconductor devices, various processing apparatuses (semiconductor-manufacturing apparatuses) are used to perform various processes, such as oxidizing, diffusing and CVD (Chemical Vapor Deposition), to process objects, such as semiconductor wafers (hereinafter, also referred to simply as “wafers”). As one type of such processing apparatuses, there has been known a batch-type heat treatment apparatus (e.g., a vertical heat treatment apparatus) that performs a heat treatment (thermal process) to a large number of wafers at a time (refer to JP2001-237238A, for example).[0003]One example of the vertical heat treatment apparatus is a low-pressure diffusion apparatus, part of which is shown in FIG. 13. The low-pressure diffusion apparatus of FIG. 13 includes: a processing vessel 3 (process tube) made of quartz that accommodates wafers therein to perform a heat treatme...

AI Technical Summary

Benefits of technology

The present invention provides a heat treatment apparatus that prevents damage to the furnace throat and prevents contamination of process objects due to chafing between the lid and throat member. This is achieved by a contact-preventing member that prevents direct contact between the lid and furnace throat under reduced pressure. The apparatus includes a processing vessel with a metallic lid and a metallic throat member, a sealing member disposed between the lid and throat member, and a contact-preventing member that prevents contact between the lid and throat member. The contact-preventing member can be easily installed and replaced, and a disengagement-preventing member is attached to the lid to further prevent unexpected disengagement of the contact-preventing member. The apparatus also includes a wide pressure-bearing area for the contact-preventing member to ensure stability and safety during use.

Problems solved by technology

Due to this, contact pressure is exerted on the furnace throat 2a, resulting in damage of the furnace throat 2a such as cracking, and generation of particles due to micro cracks.

This causes chafing between the lid 15 and the manifold 50 due to difference in their thermal expansions, resulting in metallic contamination of wafers.

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